Conveying device utilizing pressurized fluid flow



Jan. 9, 1968 c s 3,362,755

CONVEYING DEVICE UTILIZING PRESSURIZED FLUID FLOW Original Filed Feb.19, 1958 INVENTORI EL M62 F250 Mac/ 5 United States Patent 3,362,755CGNVEYMG DEVHIE UTILIZING PRESSURIZED FLUID FLQW Elmer Fred MacQ, WillowLane,

Vermilion, Ghio 44089 Continuation of application Ser. No. 716,243, Feb.19, 1958. This application Aug. 23, 1962, Ser. No. 223,863

2 Claims. (Cl. 30229) The present application in a continuation of mycopending application, Ser. No. 716,243, filed Feb. 19, 1958, which is acontinuation-in-part of application Ser. No. 446,025, filed July 27,1954, and now abandoned.

This invention relates to supporting devices and more particularly tosupporting slides and conveyors wherein a fluid is utilized as asupporting film for a moving element.

It has been discovered that an object may be supported for free,substantially frictionless movement on a thin film fluid under pressure.To lift an object for free relative movement, fluid under pressure isprovided over an an entire confined area of confrontation defined bycornplemental surfaces of a slide support and the obpect to besupported.

This discovery may be utilized by providing a slide support having acavity and a foraminous wall defining a smooth open supporting surface.When a base surface of an object is placed in facial confrontation withthe smooth slide support surface, fluid under pressure may be passedthrough the foraminous wall to lift the body. To accomplish this, fluidunder pressure is introduced into the cavity. The fluid passes throughthe foraminous wall in a unform fashion over the entire surface. Thus, athin film of fluid under pressure is formed between the object basesurface and the slide support surface.

The film consists of a moving fluid which is constantly escaping aroundthe periphery of the area of confrontation and being replenished by afresh supply of fluid passing through the foraminous wall.

As fluid under pressure is passed through a restriction, a pressure dropis experienced. The greater the flow the greater the pressure loss, andconversely, the lower the fluid flow the lower the loss.

Thus, when fluid is passed through a foraminous wall having an area ofconfrontation on one side, a fluid film having load supportingcharacteristics will be formed over the area of confrontation. If theratio weight of Object to be supported area of confrontation is high,the load supporting film will be of high pressure in a properly designedsystem so as to support the object. The flow of fluid on the other handwill be relatively low,

and hence the pressure drop will be low. Conversely, if the object islight, the flow and the pressure drop will be relatively high and thepressure of the film will be relatively low.

If the object is formed symmetrically, the film will be of uniformdimension. The filrn will, however, generally be of varying thicknessand pressure since the weight of the object will not be symmetricallydistributed. The heavy side of the object will be relatively close tothe slide support and the film will be thin and of high pressure. Thefluid flow on the heavy side will thus be low as will the pressure drop.Conversely, on the light side of the object, the film pressure will below and the pressure flow and drop relatively high. Thus, even thoughthe confronting surfaces are not precisely parallel, a thin lubricatingand supporting film will be maintained. This feature of a properlydesigned system is known as automatic zone feedback compensation orsimply as load zone compensation.

3,362,755 Patented Jan. 9, 1968 One of the principal objects of thisinvention, then, is to provide a slide support having a smooth, opensurface and a foraminous wall through which fluid under pressure may bepassed to form a lubricating and supporting fil-rn having load zonecompensation.

In the present invention a slide support which provides such a thin filmof supporting fluid by means of a porous wall is disclosed. It has alsobeen discovered that an object may be supported and lubricated by a thinfilm provided by the object itself. This concept is disclosed in morecomplete detail in the copending application for patent Ser. No.433,946, filed June 2, 1954, entitled Method and Apparatus for ProvidingMobility, now abandoned in favor of continuation-impart application Ser.No. 737,969, filed May 26, 1958.

While it will be apparent to a mechanic skilled in the art that theprinciples of this invention are applicable to many devices in whichrelative unconfined movement along an open surface is desired, anamusement device is here set out as one embodiment of the invention andto disclose related improvements pertaining to this particularembodiment.

One of the objects of this invention is to provide a slide support inwhich a foraminous member having a source of fluid under pressureconnected therewith forms a relatively frictionless surface for slidablysupporting a mOV- ing element.

Another object of this invention is to provide a toy in which aforaminous wall is formed in turns and dips and is connected to a sourceof fluid under pressure for carrying an element thus simulating a rollercoaster, ski slide, or other amusement device.

A still further object of this invention is to provide an amusementdevice in which a fluid foraminous floor is connected with a source offluid under pressure, the upper surface of the floor having a film offluid thereon for supporting in a relatively frictionless manner anindividual having flat bottom skis or runners on which to stand duringskating movements over the floor.

Another important object of this invention is to provide a conveyorwherein an inclined wall is permeable to allow the passage of fluidconducted thereto from a source of supply, thus establishing the film offluid between the wall and a tray, belt, or a series of interconnectedtrays traversing the surf-ace of the inclined wall.

The embodiments of this invention include a wall of foraminous materialcapable of allowing the restricted passage of fluid therethrough in sucha manner that a cooperating device such as a tray or pan is supportedfree of the wall on a relatively frictionless film of fluid. Theforaminous wall is incorporated in a structure having a plenum chamberor duct in communication with the Wall. Air, water, or other fluids maybe utilized as the supporting medium depending on the desiredcharacteristics. The foraminous wall is formed to the desired shape toguide and support a moving body throughout a path of either a straightincline or dips and curves or over a horizontal straight path.

The structure of the foraminous or permeable wall is such that as thefluid flows therethrough, a pressure drop results even if the flow isunrestricted at the surface by the presence of an object to be supportedby the load supporting film. At this condition the residual pressure atthe surface would be less than the supply pressure. If a portion of thepermeable wall is covered by a tray, flat plate, belt, or similardevice, the flow through the wall would be restricted in that area withthe result that the pressure drop through the Wall would be reduced thusproducing a residual pressure between the wall and the plate approachingthat of the source of supply. Accordingly, con

siderable loads may be placed on trays or belts which are supported outof contact with the slide with the only resistance to movement being thevery small friction produced by the viscosity of the fluid beingutilized. The usefulness and novel eflects which can be achieved byutilizing this invention result in articles of manufacture of unusualnature.

Accordingly, it is one of the most important objects of this inventionto provide a structure in which a wall of foraminous material regulatesthe flow of fluid over an area to establish a supporting film of thefluid on which elements may be moved with relatively little forcerequired.

Other objects and advantages, more or less ancillary to the foregoing,and the manner in which all the various objects are realized will appearin the following description, which considered in connection with theaccompanying drawings, sets forth the preferred embodiment of theinvention.

In the drawings:

FIGURE 1 is an elevational view of a ski slide embodying my invention;

FIGURE 2 is a sectional view taken along line 22 of FIGURE 1;

FIGURE 3 is a view similar to FIGURE 2 showing a modified form of theski slide;

FIGURE 4 is a sectional view of a skating floor;

FIGURE 5 is a side view of a runner for operation on the skating floor;

FIGURE 6 is a sectional view taken along line 6-6 of FIGURE 5 FIGURE 7is a sectional view of a conveyor taken along line 77 of FIGURE 8;

FIGURE 8 is a sectional view taken along line 8-8 of FIGURE 7; and,

FIGURE 9 is a View similar to FIGURE 8 of a modified form of theconveyor.

The invention is incorporated in a ski-slide type of device shown inFIGURE 1 wherein the frame of the slide is designated by the numeral I0.A track 12 is supported by the frame 10 in the desired configuration asrequired by the type of toy design. In FIGURE 1 the toy is illustratedas a ski slide but it is understood that it may also be in the form of aroller coaster utilizing turns and additional dips. This slide apparatusmay be used wherever it is desired for an object to move along apredetermined path, the only force required for imparting motion to theobject being that of gravity. The frame 10 serves as a housing having arelieved area which together with the slide 12 defines a cavity 14 insuch a manner that a Wall of the slide 12 is exposed to the interior ofthe cavity 14. Supporting struts 16 are disposed between the slide 12and the frame 10 to strengthen the slide 12 in order to carry the loadsimposed thereon. The struts 16 are perforated to allowinter-communication between the sections of the cavity 14 and are soarranged that they do not cover an appreciable part of the surface ofthe slide 12.

The floor 12 must be sufliciently foraminous to permit fluid underpressure to flow from the cavity 14 through the floor 12 to the outersurface of the floor in order that a film of fluid under pressure may beformed at any location on the floor. Thus, when an object beingsupported is moved across the floor 12 in translational movement, thesupporting fihn is created wherever the object is. To accomplish thisthere must be a plurality of small holes or pores in the body. Asintered material such as a sintered bronze is an excellent example of aworkable material since relatively uniform porosity is providedthroughout the entire floor or track. A plurality of holes may bedrilled or formed in an otherwise solid material to provide the sameeffect. The term foraminous has been selected because it is a term whichdefines all types of porosity operable in this invention including bothorifice and permeable types of restrictions to obtain the desired loadzone compensation. The degree of porosity will vary widely according tothe fluid, the weight and size of the object being supported, and othervariables.

To obtain proper load zone compensation and the above-mentioneddesirable operating characteristics with an optimum overall system, theforaminous wall and confronting surfaces must be carefully engineered.To provide adequate load zone compensation and a safe value of minimumload supporting film thickness while yet maintaining a low rate of fluidflow under all operating conditions the following relationship should bemaintained:

p /p is from 1.25 to 5.0 where p is the supply pressure,

p; is the average film pressure of the load supporting film in the caseof a porous surface or the load supporting film pressure at the orificeexit in the case of other means of zone compensation.

Many operating and design variables such as orifice size and roughness,wall thickness, fluid viscosity, temperature, etc. must be properlyconsidered so as to provide the safe minimum load supporting filmthickness generally under 0.005 inch and normally about 0.001 inch.

The foraminous support surface may be porous (such as sintered bronze)or may contain other forms of load zone compensation such as anorifice-pool configuration or it may simply contain a series of verysmall orifices drilled, or punched or otherwise formed. Examples ofvarious types of foramina may be found in the copending application forpatent Ser. No. 643,665; filed Mar. 4, 1957 for a seal, now Patent No.2,907,594, issued Oct. 6, 1959. In all cases, however, the ratio p p isgreater than 1.25.

Expressed in another way, the load zone compensation should provide anaverage pressure drop of about /5 to Vs as fluid is passed from thesource of supply to the load supporting film when the device is inoperation. Thus, the average pressure in a load carrying film will be nomore than /5 and at least /s of the pressure of the supplied fluid inthe chamber or cavity 14.

A conduit 20 is connected to the frame 10 to open into a fluidaccumulator 22 through aperture 18. A pump 24 compresses the air in theaccumulator 22 for subse quent discharge through the conduit 20 and intothe cavity 14. A valve 26 in the conduit 20 controls the flow of fluidtherethrough and may be remotely actuated by a trip device 23 at thestarting point of the ski slide. An alternate fluid supply may beconnected to conduit 20 by a conduit 30. A check valve 32 in conduit 30prevents the loss of fluid when pump 24 is being used as the compressor.

A control 34 such as a cam and lever arrangement positions the end ofthe slide 12 and the portion of the frame forming the cavity thuscontrolling the path of flight of an object which has just traversed theslide. In FIGURE 2 a toy skier 36 is shown having skis 38 aflixedthereto for confronting the upper surfaces of the slide 12. Slide 12 hasupwardly extending portions 40 having their inner surfaces arranged todischarge fluid laterally against the skis 38 thus maintaining the skis38 spaced from the portions 40. In this Way the skier 36 is guided andsupported along the slide 12.

In FIGURE 3 a slide 12 is shown having a center guide 42 in addition tothe portions 40 for maintaining the direction of travel of a skier. Theforaminous material forming the slide 12 has its faces sealed which arenot opened to the cavity or do not function with the object to besupported and guided. This seal may be accomplished by portions of theframe including a sealing lip 44 which prevents the loss of fluid fromsurfaces having no function. Burnishing, tape, paint, cement, or othermaterials may also be applied to the permeable material to regulate theareas from which the fluid is to be discharged.

The ski slide 12 is adaptable for use as a slide for sporting events outof season since the slide 12 and the skis 38 may be proportioned tosupport the weight of a man and provide conditions even morefrictionless than snow or ice.

A skating floor or rink 46 is shown in FIGURE 4, the

floor 46 being formed from foraminous material which will allow fluid topermeate to the upper surface thereof.

A base 48 has a fluid-tight lower wall and sides for supporting thefloor 46 with a cavity 50 adjacent the lower face thereof for receivingfluid from an inlet 52 which is connected to a source of fluid underpressure which may take the form of a pump and accumulator, water supplysystem, overhead tank, or other system capable of continuously supplyingfluid at a nominal pressure. A plurality of struts 54 support the floor46 and the load carried thereby.

To better illustrate the principles embodied in the device of FIGURES 4through 6 dimensions of a relatively large embodiment of this inventionare provided. The foraminous floor 46 in a a skating rink may, forexample, have a dimension of 10 feet by 20 feet. A fluid such as wateris supplied to the cavity 50 under the foraminous floor 46 to providethe desired fluid under pressure to create the film. In this example thewater would be supplied under a pressure of approximately 5 pounds persquare inch, and it will flow through the foraminous floor 46 at therate of about 4 gallon per minute per square inch when the rink is notin use. When the rink is in use, the flow, of course, will be reduced inthose areas where skaters are present because, as has been previouslydescribed, the pressure drop will decrease and therefore the flow willreduce. In this embodiment the flow is preferably circulated by abuilt-in pump.

The total pressure applied against the foraminous floor from the cavityside is approximately pounds per square inch. In the present example, asin the other embodiments of this invention, sintered bronze is asuitable material for construction of the foraminous floor. The floor 46in the by 20 foot embodiment would be approximately one and one-halfinches in thickness. In this instance the strut supports 54 would beabout one-quarter inch in diameter and one-sixteenth inches in lengthand would be provided about the foot apart to reinforce the floor.

Sizes of skates such as those shown in FIGURES 5 and 6, vary with thesize of the skater. As an example, a skater having a weight under 100pounds would use a pair of skates each of which has approximately 40square inches of surface and each of which would be approximately 4 by10 inches in dimension. A skater of from one hundred to two hundredpounds would require skates having about 80 square inches each. Suchskates can suitably be constlucted 5 by 16 inches in dimension.

The skate which is used on the floor 46 is illustrated in FIGURES 5 and6 in which a flat plate 56 having a plane bottom on which the userstands. The bottom of the skate may be rigid or flexible. A resilientedging 58 is mounted on the periphery of the plate 56 and functions asan edge to propel and brake the skater when the skate is tilted. Thisedge also functions as a bumper to prevent damage to another skate andthe permeable floor or to prevent injury to the body of a wearer. Theflat undersurface plate 56 when confronting the floor 46 and approximatethereto is supported by the film of fluid which is distributed over thesurface of the floor by the permeable nature of the material and thecavity acting as a plenum chamber beneath the lower surface of tthefloor 46. The fluid pressure and the area of the plate 56 are adjustedto support the weight of the individual standing on the plate 56.

In FIGURES 7, 8 and 9 a conveyor is shown embodying the inventiondisclosed herein having a slide 60 formed from a foraminous material,the slide 60 being sloped to allow the force of gravity to producetranslation of the object to be conveyed. A fluid-tight frame 62supports the slide 60 and forms a cavity 64 for receiving fluid underpressure to be discharged through the slide 60. A plurality of struts 66support the slide 60 and the load thereon, the struts 66 beingperforated with relatively large holes or slots to allowintercommunication between the sections of the cavity 64. A pump 68provides the fluid under pressure which is pressurized in an accumulator70 and piped to the cavity 64 through a conduit 72 having a controlvalve 74 therein for regulating the flow of fluid through the cavity. Analternate fluid supply may be connected to conduit 72 by a conduit 73.The load to be conveyed is placed on a pallet 76 which has bottom andside surface conforming to the surface of the slide 60. The pressure ofthe fluid in the cavity 64 produces flow through the slide 60 anddevelops a continuous film of fluid intermediate the slide 60 and thepallet '76 which is relatively frictionfree. Since the friction is sosmall a slight inclination in the slide 60 is suflicient for the pallet76 to gravitate therealong with no external urging required. The pallet76 may take the form of an individual tray, a series of connected trays,or of a continuous belt which is driven by an external means in either ahorizontal or inclined direction.

In FIGURE 9 the slide 78 is curved to provide a concave upper surfacefor carrying a concave tray or belt 80. Slide 78 is formed of apermeable material and supports the tray 80 in the same manner as theslide 60 supports the tray 76. The arcuate slide 78 and thecorrespondingly shaped tray 80 is particularly adapted for carryingsmall articles or granular material which would not repose on a fiattray. Further, the tray 80 is self-centering since the forceof gravitywould tend to hold the tray 80 in the lowermost area of the slide 78.This shape is particularly desirable in the operation of a conveyor beltsince any material carried thereon would not tend to be lost from thebelt surface. It is understood that slides of other shapes arecontemplated as might be required for special purposes and would fallwithin the scope of this invention.

The runners, pallets, belts, and trays which form the movable loadsupporting members confronting the permeable wall may be of either rigidor flexible material to conform to the supporting surface or accomplisha function required by the object being carried. The embodiments of thisinvention are illustrated in general as toys or amusement devices.However, it is contemplated that essentially these same structures andprinciples are usable in large scale and in industrial applications, forexample, the conveyor system.

A device has thus been described which has a foraminous wall with asmooth, open outer surface and an inner surface communicating with meansfor supplying fluid under pressure to provide a zone compensatedsupporting and lubricating film of fluid between the outer surface and acomplemental surface on an object to be supported when the object isplaced with such outer and complemental surfaces in face-to-facerelationship.

Although the foregoing description is necessarily of a detailedcharacter, in order that the invention may be completely set forth, itis to be understood that the specific terminology is not intended to berestrictive or confining; and that various rearrangements of parts andmodifications of design may be resorted to without departing from thescope or spirit of the invention as hereinafter claimed.

What is claimed is:

1. A fluid lubricated conveying device for facilitating movement of anobject comprising in combination a foraminous wall, said wall having abottom surface, an upper, object-confronting surface, and upwardlyextending side Walls extending above said object confronting surface,said side Walls and said object-confronting surface defining achannel-shaped conveying path for said object, means for suppling fluidunder pressure to said wall to produce a supporting film of fluidbetween the object and said object-confronting surface by fluid flowthrough said wall and to laterally center the object in saidchannel-shaped conveying path by fluid flow through said side walls, andmeans on at least the portion of the wall including said bottom surfaceand said object confronting surface for restricting the rate of fluidflow therethrough to produce an average pressure drop thereacross in theabsence of an object on said object-confronting surface.

2. A lubricated conveying device for facilitating movement of an objectcomprising in combination a channelshaped foraminous support, saidsupport having a bottom surface, an upper object-confronting surface,and opposed side walls extending above said object-confronting surface,a forarninous center guide between said side Walls and coextensivetherewith, said side walls and said center guide having formaiuaearranged to discharge fluid laterally against an object disposedcontiguous to said object confronting surface, means for supplying fluidunder pressure to the bottom surface of said support and to said sidewalls and said center guide so that a fluid film is formed between theobject and said object confronting surface and so that the object iscentered between said guide and said side walls, and means on at leastthe portion of the support forming said object confronting surface toproduce an average pressure drop thereacross even in the absence of anobject on said object confronting surface.

References Cited UNITED STATES PATENTS 756,600 4/ 1904 Dodge. 1,971,8538/1934 Ihlefeldt 3023l X 2,174,716 5/1938 Bethell 27256.5 2,538,9721/1951 Magnan-i. 2,678,237 5/1954 Allander et a1 302-31 2,708,602 5/1955Galle 302-29 2,805,898 9/1957 Willis 30229 F. BARRY SHAY, PrimaryExaminer.

RICHARD C. PINKHAM, E. C. BLUNK, F. B.

LEONARD, Examiners.

1. A FLUID LUBRICATED CONVEYING DEVICE FOR FACILITATING MOVEMENT OF ANOBJECT COMPRISING IN COMBINATION OF FORAMINOUS WALL, SAID WALL HAVING ABOTTOM SURFACE, AN UPPER, OBJECT-CONFRONTING SURFACE, AND UPWARDLYEXTENDING SIDE WALLS EXTENDING ABOVE SAID OBJECT CONFRONTING SURFACE,SAID SIDE WALLS AND SAID OBJECT-CONFRONTING SURFACE DEFINING ACHANNEL-SHAPED CONVEYING PATH FOR SAID OBJECT, MEANS FOR SUPPLYING FLUIDUNDER PRESSURE TO SAID WALL TO PRODUCE A SUPPORTING FILM OF FLUIDBETWEEN THE OBJECT AND SAID OBJECT-CONFRONTING SURFACE BY FLUID FLOWTHROUGH SAID WALL AND TO LATERALLY CENTER THE OBJECT IN SAID CHAN-